System and method for coating a fire-resistant material on a substrate

ABSTRACT

A method for coating a fire-resistant substance onto a carrier veil and products containing fire-resistant substances are provided. The method includes delivering a pliable carrier veil in a traveling web, drawing the carrier veil web through a reservoir defined by a nip of two rollers and containing the fire-resistant substance, where the carrier veil is coated with the fire-resistant substance. The method also includes controlling the amount of fire-resistant substance on the carrier veil web by setting a nip dimension between the two rollers, passing the carrier veil through the nip of the two rollers and providing the fire-resistant substance as a slurry suitable to coat the veil exiting the nip with a layer effective to provide a selected fire resistance. Heat is applied to the carrier veil sufficient to accelerate a curing reaction in the fire-resistant substance. A fire-resistant product includes a glass-based web, and a magnesium oxychloride complex materially coupled to the web, where the complex includes: MgCl 2 .mMg(OH) 2 .nH 2 O; where m is between about 3 and about 7, and n is between about 6 and about 10.

FIELD OF THE INVENTION

The present invention relates to processes for coating fire-resistantmaterials onto a substrate, and more particularly to a process forcombining a coated substrate and an impregnated veil material to form areinforced substrate having fire-resistant properties.

BACKGROUND OF THE INVENTION

Fire retardant chemicals have been used to impregnate cellulosic-basedmaterials such as plywood, oriented strand board (OSB), andparticleboard panels, in order to yield fire-resistant products.However, impregnation with fire retardant chemicals is an expensiveprocedure and a complicated process, because, in order to be effective,the chemicals must be applied under pressure in a closed pressurecylinder, which requires that a vacuum be pulled first on the load toextract the air from the wood cells prior to pressurization.Furthermore, impregnation of cellulosic materials with fire retardantchemicals adversely affects the long-term structural stability of thecellulosic materials.

Fire retardant coatings have also been used to reduce the surfaceflammability and improve burn-through resistance of wood products, andother flammable materials. Compositions and uses for fire retardantcoatings are discussed further in U.S. Pat. Nos. 5,130,184; 4,818,595;4,661,398; and 4,572,862, each of which are incorporated by reference intheir entireties. Application of fire retardant coatings by brushing,spraying and sheet lamination is known. Brushing or spraying applicationmethods alone, however, can make it difficult to achieve a coatinghaving a uniform thickness and desired surface characteristics. Inaddition, the coatings may be required to dry or set before additionalcoatings can be applied in order to build a sufficient volume ofmaterial to achieve the desired fire-resistant properties. Applicationby preparing a separately formed sheet of fire retardant coatingmaterial and laminating it to the substrate involves the use of anadhesive layer and has disadvantages related to the process ofmanufacturing.

Fire retardant coatings can also be used to coat strands of fiber or toimpregnate fabrics. Spray-coated strands of chopped fiberglass, forexample, may be used as a fire-resistant coating on cellulosic panelsubstrates, as in the Blazeguard® construction panel product. Suitablefabrics used in fiber impregnation with fire-retardants include, forexample: non-woven needled polyester fabrics, non-woven fiberglass orglass-based veil, woven fiberglass, woven carbon cloth, and woven aramidfabric (“Kevlar”). Fabrics of quartz, nylon, or other natural orsynthetic or inorganic fibers, woven or unwoven, may also be used.However, the process of impregnating fabric with a fire retardantcoating raises challenges. The volume of fire retardant coatingimpregnated in fabrics can vary, depending on the thickness and porosityof the fabric and the volume and physical qualities of the coatingmaterial used to impregnate the fabric. Variations in the volume of theimpregnated fabric may affect the effectiveness of the fire retardantcoating when the fabric is applied to a flammable substrate. This maymake it difficult to consistently produce a product with a desired levelof fire resistance.

Because many building products with greater or lesser fire-resistantqualities compete as commodities, production methods used to make suchproducts must be efficient and rapidly scalable in volume. In addition,production methods also need to yield consistent products that meet thestandards of the applicable building code.

It is an object of the present invention to provide a system and methodfor efficiently coating substrates with fire retardant materials inwhich the dimensions and/or volume of the coating is controlled whileyielding a fire-resistant product that maintains a high degree ofstructural integrity over time, at high temperatures, and duringexposure to high temperatures over extended periods.

BRIEF SUMMARY OF THE INVENTION

According to an embodiment of the present invention, a method forcoating a fire-resistant substance onto a carrier veil is provided. Themethod includes the steps of: delivering a pliable carrier veil in atraveling web, and drawing the carrier veil web through a reservoirdefined by a nip of two rollers containing the fire-resistant substance.The carrier veil is coated with the fire-resistant substance. The methodalso includes controlling the amount of the fire-resistant substance onthe carrier veil web, where controlling includes setting a nip dimensionbetween the two rollers, passing the carrier veil through the nip of thetwo rollers and providing the fire-resistant substance as a slurrysuitable to coat the veil exiting the nip with a layer effective toprovide a selected fire resistance, and applying heat to the coatedcarrier veil sufficient to accelerate a curing reaction in thefire-resistant substance. In some embodiments, the carrier veil is aglass-based veil. Alternatively, the carrier veil may be a boundfiberglass mat. The reservoir of fire-resistant substance may include anamount of substance fed to and maintained at an adjustable nip that ispredetermined and/or controlled. The fire resistant substance mayinclude a wet slurry that is a precursor to magnesium oxychloride, or awet slurry that is a precursor to magnesium oxysulphate, or combinationsof both. For example, when the magnesium oxychloride-basedfire-resistant substance completes its curing process, the compound ismagnesium oxychloride having the formulation: MgCl₂.mMg(OH)₂.nH₂O, wherem is between about 3 and about 7, and n is between about 6 and about 10,as determined by x-ray diffraction or x-ray phased analysis.Alternatively m may be about 5 and n may be about 8. For purposes of thepresent invention, the term slurry means a wet mixture of a precursormaterial, that, when cured, yields magnesium oxychloride, magnesiumoxysulphate, or combinations of both. Examples of such slurries areidentified in previously mentioned U.S. Pat. Nos. 5,130,184; 4,818,595;4,661,398; and 4,572,862.

In certain embodiments, controlling the amount of fire-resistantsubstance includes depositing a selected amount of fire-resistantsubstance per square unit of substrate.

According to certain embodiments, the method may further include coatinga first layer of a fire-resistant material on a substrate, anddepositing the coated carrier veil as a second layer over the firstlayer of fire-resistant material. The substrate receives the coatedcarrier veil as it passes under the two rollers where the veil iscoated. In this embodiment, the first layer may be roll coated, flowcoated, or spray applied. The substrate may also be pre-processed toincrease its surface area in order to enhance bonding with the firstlayer of fire-resistant substance. In some embodiments, the substratecontains wood products and the step of coating a first layer of fireretardant substance to the substrate includes, at a first station,coating with a roll coater a first slurry of fire retardant materialdiluted sufficiently to wet cells of the wood products. In someembodiments, the carrier veil may be a glass-based continuous webextending between multiple substrates. The substrates may be positionedwith a predetermined gap which is substantially preserved until afterreceiving the deposited coated veil. A cutting means may be subsequentlyapplied to the continuous web at the predetermined gap in order toseparate the multiple substrates.

In addition to coating a first layer of a fire-resistant material on asubstrate followed by depositing the coated carrier veil, methods mayfurther include depositing a third layer of fire-resistant substanceover the first layer and the coated carrier veil. The third layer may bedeposited by roll coating, flow coating, or spray coating, for example.When heat is applied to the layers of fire-resistant-substance, infraredradiation may be used in order to initiate a penetrating curing processof the layers of fire-resistant material. In some embodiments, theapplied heat source is removed and the heated layers of fire-resistantsubstance are allowed to cure. Alternatively, the substrate may beremoved from heat and a finishing layer may be applied over a coatedportion of the substrate. An additional layer may be applied over thethird layer of fire-resistant material which may include, for example,another substrate, wood veneer, laminates, paper and plastic film. Incertain methods, the substrate may be weighed before coating thesubstrate with the first layer and after coating the substrate with afinal layer of fire-resistant material, i.e., the second layer or thirdlayer of fire-resistant material.

According to another embodiment of the present invention, afire-resistant product includes a magnesium oxychloride complex,MgCl₂.mMg(OH)₂.nH₂O, where m is between about 3 and about 7, and n isbetween about 6 and about 10, and a glass-based web materially coupledto the complex. In a more specific embodiment, m is about 5 and n isabout 8. According to certain embodiments, the web is impregnated by thecomplex.

In yet another embodiment, a fire-resistant product includes aglass-based web comprising a first side and a second side, a magnesiumoxychloride complex materially coupled to the web, where the complexincludes: MgCl₂.mMg(OH)₂.nH₂O, where m is between about 3 and about 7,and n is between about 6 and about 10, and a layer of magnesiumoxychloride complex materially coupled on a first or second side of theweb, where the complex includes: MgCl₂.mMg(OH).nH₂O, where m is betweenabout 3 and about 7, and n is between about 6 and about 10. In a morespecific embodiment, the complex is composed of MgCl₂.mMg(OH)₂.nH₂O,where m is about 5 and n is about 8. In a further embodiment, anotherlayer of magnesium oxychloride complex is materially coupled on theother of the first or second side of the web, where the complexincludes: MgCl₂.mMg(OH)₂.nH₂O, where m is between about 3 and about 7,and n is between about 6 and about 10. In a more specific embodiment, mis about 5 and n is about 8 for the another layer of the magnesiumoxychloride complex. In some embodiments, at least one of the layers ofa slurry that is a precursor to cured magnesium oxychloride is rollcoated on the web.

In another embodiment, a fire-resistant product includes a glass-basedweb, a magnesium oxychloride complex materially coupled to the web,where, when cured, the complex includes: MgCl₂.mMg(OH)₂.nH₂O, where m isbetween about 3 and about 7, and n is between about 6 and about 10, alayer of magnesium oxychloride complex materially coupled on the web,where the complex, when cured has the formulation: MgCl₂.mMg(OH)₂.nH₂O,where m is between about 3 and about 7, and n is between about 6 andabout 10, and a substrate materially coupled to the layer of magnesiumoxychloride complex. In a further embodiment, another layer of magnesiumoxychloride complex is materially coupled to the web, where the complex,when cured has the formulation: MgCl₂.mMg(OH)₂.nH₂O, where m is betweenabout 3 and about 7, and n is between about 6 and about 10. According tosome embodiments, each cured magnesium oxychloride complex is comprisedof MgCl₂.mMg(OH)₂.nH₂O, where m is about 5 and n is about 8.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a plan view of a production line that may be implementedaccording to embodiments of the present invention.

FIG. 2 depicts a schematic block diagram of another production line thatmay be implemented according to embodiments of the present invention.

FIG. 3 is an illustration of a reverse roll coater used in oneembodiment.

FIG. 4 is an illustration of a top roll coater that includes an unwindstand for supporting a web or continuous roll of veil material forimpregnation with fire-resistant slurry and subsequent placement on asubstrate.

FIG. 5 is a view of a roll coater that coats a fire-resistant slurryonto a carrier veil.

FIG. 6 is a is a view of an alternate roller pair that coats afire-resistant slurry onto a carrier veil.

FIG. 7 is a view of a pan bath for coating a fire-resistant slurry ontoa carrier veil.

DETAILED DESCRIPTION OF THE INVENTION

Fire-resistant Coating Overview. For purposes of the present discussion,the term fire-resistant encompasses any type of fire barrier substance,such as fire retardants, flame retardants, and flame-resistant materialsthat can be prepared in the form of a slurry; and the terms impregnateand coat encompasses any degree, level, or amount of intake of slurryinto a porous carrier material, such as saturation, dispersion with someentrained air or surface coating.

Fire-resistant coatings such as Pyrotite™, a magnesium oxychloridematerial with filler, and other similar substances, e.g., magnesiumoxychloride and/or magnesium oxysulphate or the like without filler, arecementitious materials that provide fire barrier protection and may beused to coat substrates, according to embodiments disclosed herein.Specific chemistries of fire barrier materials that provide fireprotection, which may be used in accordance with the systems and methodsof the present invention, are described in U.S. Pat. Nos. 4,572,862;4,818,595; and 5,039,454, which are hereby incorporated by reference intheir entireties. Typical fire-resistant coatings contain 3-7 molarmagnesium oxychloride, are 10-125 mils thick, and include a filler suchas inert sand, gravels, crushed rocks, silica flour, pumice,vermiculite, volcanic ash, perlite, wood shavings, and/or mineralfibers. The thickness of the coating on the substrate varies accordingto the level of fire resistance desired in a particular application, andthe filler in the slurry varies depending on desired handling qualitiesduring manufacturing and resulting product characteristics. Substratesthat may be coated with fire-resistant materials may include, forexample, wood, plywood, OSB, plastic, metals, wallboard, medium densityfiberboard (MDF), and particle board, or any material or compositematerial suitable for coating. Typical substrates may take the form of aplanar sheet, such as a 4 foot by 8 foot panel, but smaller and/orlarger substrates are also equally possible.

According to the present invention, systems and methods for forming afire-resistant layer on a substrate typically include substratepre-treatment, coating, heating, curing, finishing, and stacking.

Pre-treatment. According to certain embodiments of the presentinvention, a substrate to be coated with fire-resistant material may bepre-treated in order to increase the bonding area of the substrateavailable at the microscopic level and to roughen the surface. Theincreased bonding area provides an increased amount of available surfacefor fire-resistant material to adhere. This may be particularly usefulfor composite cellulosic materials formed with pressure and/or heat thathave resulting smooth surfaces. Scuffing, sanding, and introducingsubstrates to a chemical bath are methods to increase the substrateavailable bonding area, because, when cellulosic material is subjectedto such treatments, interstitial spaces open to increase the porosityand permeability of the cellulosic surface. This permits increasedpenetration by wet, fire-resistant materials. In addition to openinginterstitial spaces in cellulosic material, scuffing may create asurface toothing allowing for increased physical bonding with the wet,fire-resistant materials. This is because as a cementitiousfire-resistant substance cures and dries, it adheres more strongly to arough surface, as compared to a smooth surface.

Coating Methods. Coating substrates with fire-resistant materials,according to the present processes, includes depositing flowable orviscous layers of a homogenous mixture (often called a slurry) offire-resistant material onto a substrate. For example, one or morerollers, flow coaters, or sprayers may be used as vehicles to deposit alayer of fire-resistant material on a scuffed substrate. In one example,when the substrate is passed between a feed roll and a coating roller,the flowable material is deposited onto the substrate. The thickness ofthe layer of flowable material deposited may be controlled by adjustingthe mechanical features of the coating machine such as the nip, e.g.,the distance between rollers, and the speed at which the rollers rotate.For reverse roll coaters, for example, the coating roller deposits morematerial as it rotates faster and vice-versa. In addition, the thicknessof the layer of flowable material may be controlled by controlling thepressure one or more rollers exerts on a coated substrate. Typically,the thickness of the finished layer of fire-resistant material is0.010-0.125 inches or 10-125 mils. Depositing an initial slurry offire-resistant material on the entire surface of a substrate serves as awetting step in order to set up a strong, continuous bond between thesubstrate and the fire-resistant material, e.g., between cells on a woodsubstrate and a slurry. Complete wetting of the surface is desirable inorder to begin the penetration process of the fire-resistant materialinto the substrate. A strong bond between the board and thefire-resistant material also improves the foundation for layers that aresubsequently deposited. Without wetting of the substrate surface, anyadditional layers deposited on the substrate may bond to it lessstrongly.

Additionally or alternatively, fire-resistant material may be depositedon, or may impregnate or coat, a web or veil of carrier material, whichmay subsequently be deposited over a substrate. For example, one or morerollers, flow coaters, or sprayers may be used as devices to depositfire-resistant material on a veil material. Additionally, a pan bath maybe used to impregnate a veil material. Veil material may include avariety of pliable and porous fabrics such as woven or spunboundfiberglass, polyester, nylon, wool, carbon steel, or other fiber orfilament materials suitable for receiving viscous fire-resistantcoating. Preferably the veil material is available in a continuous rollseveral hundred feet long and at least as wide as the entire substrate(typically four feet), so that a continuous feed of a single web ofcoated carrier material onto the substrate may occur. Alternatively, theveil material may be slightly narrower than the width of the panel foruse with panels having beveled edge-treatment, for example.

One suitable veil carrier material is a wet-formed glass fiber veilcomprised of randomly dispersed glass fiber bonded together with aresinous binder system. While light in weight, the veil must havesufficient durability to be spooled out, coated and placed on thesubstrate. Several different grades may be used, with a nominal weightof 1.3 to 2.5 lbs per one-hundred square feet (CSF). Availablecommercial veils with these weights have the following furthercharacteristics:

Tensile MD Cure (Hot Wet Weight Min./Roll (avg.) Squareness RatioTensile Retention) 1.35 lbs./csf 60 2.5 Min. 60%  1.6 lbs./csf 60 2.5Min. 60%  1.8 lbs./csf 60 2.5 Min. 60% 2.35 lbs./csf 65 2.5 Min. 60%

In some instances the veil material is wider than the substrate in orderto ensure complete substrate coverage. For example, a mat or veil offiberglass material having the same or slightly greater width as itstarget substrate may pass through a reservoir of viscous fire-resistantmaterial and then be aligned with and applied to the surface of thesubstrate. In one embodiment, a substrate having a first layer ofdeposited fire-resistant material may be covered with a web of coated orimpregnated fiberglass material that provides a second layer offire-resistant material. The fire-resistant material on each of thesubstrate and the fiberglass material come together to form anintimately strong and continuous bond without requiring an adhesive.Removing use of additional adhesives reduces the number of steps inmanufacturing the fire-resistant coated substrates, thereby simplifyingthe manufacturing processes and reducing manufacturing costs. Inaddition, adhesives may be undesirable in fire-resistant substrates,because they often break down in the presence of moisture and heat.Furthermore, using adhesives in the manufacture of fire-resistantsubstrates adds production time, creates the presence of solvents andVOCs, and requires handling and storage.

The web or veil carrier material may have a variety of thicknesses anddensities, which may affect the volume of the fire-resistant materialdrawn into and held in the veil, and the resulting overall density of alayer deposited by this means. The thickness of the mat or veil is onedeterminant of the volume of the fire-resistant coating residing on andin the carrier material and the overall density of the impregnated veil.This is because, as the thickness of the mat or veil increases, theamount of fire-resistant material that can be carried by the veilincreases. Some veil materials have a degree of loft that allows bothair and the fire-resistant material to be present in the coated veil. Inaddition, the mat or veil material may be more or less impregnateddepending on the fabric dwell time in a bath, or “virtual bath” as willbe described further below, of fire-resistant material. According toembodiments of the present invention, rollers may also be used tocontrol the volume and density of the veil-borne layer, because as theveil passes through a series of rollers, fire-resistant material may besqueezed out of the veil due to the pressure the rollers exert on theveil.

A coated substrate may be further processed after application of theveil-borne layer in order to achieve a certain coating dimension orfinish, e.g., thickness and appearance. In this further processing step,an additional coating of fire-resistant material may be deposited on thesubstrate, an existing layer may be smoothed or a portion of the coatedmaterial may be removed in order to achieve a desired thickness.Machinery that may be used to add and/or control the thickness ordimensions of the coatings or their finish include for example, reverseroll coaters, flow coaters or spray nozzles for adding additional layersof fire-resistant material and rollers for compression and finish.

Mechanical features of coaters are discussed further below in relationto FIGS. 3-7.

Substrates may be passed between coaters using transport mechanisms suchas chains, rollers, or conveyor belts. This allows a substrate to passthrough multiple coaters spaced apart. For example, coaters may bearranged from 5 to 15 feet apart and may receive closely spacedsubstrates from speed-controlled transport devices, thereby enabling anear-continuous process for coating substrates with fire-resistantmaterials. Although the finished coated panels are individual units andthe substrate panels used as input to the process are also individualunits, it is desirable to make the process as continuous as possible.The veil-borne layer produced by applying fire-resistant material to acontinuous web and delivery of that coated web onto the substratepermits a continuous production process.

Curing. Curing is the process of converting a cementitious slurry into asolid. Curing is generally achieved through thermal treatment and/orexposure to ambient conditions. Partial curing means that the slurry haspartially solidified. Subsequent to the steps for coating substrates,processes for further treating coatings on the substrates may includeheat treatment. Heat treatment initiates and/or accelerates the curingprocesses of the coatings but may also drive off water that contributesto fire resistance. Controlling the amount of heat a coated substrate isexposed to may allow for controlling curing and water loss. Both thecuring rate and water content of fire-resistant layers need to fallwithin acceptable ranges in order to produce efficiently afire-resistant substrate having a specified amount of fire-resistantmaterial with the requisite properties. An oven may provide controlledheat treatment in which substrates pass through the oven along a seriesof rollers, for example. Factors that may be controlled in an oven mayinclude temperature, humidity, intensity of heating units, air speed andtransport speed.

With infrared radiation delivered from lamps or burners in an ovensetting, heat is able to penetrate through the coating outer surface tounderlying material in order to initiate and/or accelerate the curingprocess throughout the deposited fire-resistant material. In oneexample, a substrate spends 2 minutes inside of the oven in order toinitiate the curing process. Thus, depending on the length of the oven,the speed at which the substrates move will be adjusted to satisfy thedwell time requirement. Curing processes in the fire-resistant layers ona substrate need not be fully completed before exiting an oven area.Instead, the exposure to heat initiates and accelerates the curingprocesses. It is desirable to cure the fire-resistant material graduallyonce curing has been initiated, because (in general) the longer the wet,fire-resistant material is in contact with the substrate, the deeper thematerial bond becomes. However, a cure that is too slow causes aslowdown in production. Therefore, controlling the amount of time thecoated panel is exposed to curing initiation temperatures, i.e. in aheated oven, may allow for the curing process to proceed at a desiredrate while also achieving a strong material-substrate bond, i.e., a bondthat is strong enough to hold-up over time and use. Typically, thesubstrates will cure over a period of 1-3 hours after being exposed tooven heat for a short period of time, e.g., 2-4 minutes. In oneembodiment, the amount of heat delivered is measured by measuring thesurface temperature of the top of a coated substrate in the oven area.For example, it has been found that a minimum surface temperature of150-175 degrees F. (65-80 degrees C.) is desirable to initiate cure. Inanother embodiment, the amount of heat delivered is measured bymeasuring the btu's per square unit of area delivered during the time acoated substrate passes through the oven. For example, it has been foundthat a minimum btu amount of 15,000 btu's per square foot is desirableto initiate cure.

In certain embodiments, the oven may include multiple zones whereconditions may vary. For example, in a three-zone environment, a firstzone may have a temperature and humidity different from the other twozones. The speed of conveyors/rollers may also be controlled so that thesubstrates dwell in one or more of the heated environments for a setperiod of time. The treated, coated substrates with curing initiated maybe moved to open air racks which space the coated substrates about 1″apart, to allow excess heat from exothermic curing to dissipate. Theracks holding coated substrates are placed in a conditioning area whichhas an environment of controlled temperature, e.g., 60-80° F. andhumidity from 40% to 99% until the drying and curing processes arecomplete, or until the curing process has progressed enough, e.g., 1-3hours, so that the substrates can safely be finished and stacked.Facilitating the curing process by controlling the temperature andhumidity yields a cementitious material having the requisite stability,strength, and H₂O content for fire-barrier products.

In certain embodiments, finishing the cured and coated substrates mayinclude trimming any excess materials from the substrate. For example, afiberglass veil may extend beyond the edge of a substrate, or thecoating may need to be smoothed or otherwise treated for some cosmeticpurpose. Finished substrates may be stacked for subsequent sanding,painting, texturing, veneering, or other manufacturing, for example.

Production Lines. FIG. 1 depicts a plan view of a production line 100that may be implemented according to embodiments of the presentinvention. Production line 100 includes substrate feeding area 102,which transports each individual substrate 101 to a scuff sander 110.Feeding area 102 may feed substrate 101 to scuff sander 110 via apowered roller pathway, for example. In addition, or alternatively,substrate feeding area 102 may be constructed using a conveyor belt thatcontrollably feeds each substrate 101 to scuff sander 110.

Scuff sander 110 may include scuffing rolls, sanding rolls, or sandingbelts that include with bristles or other sanding materials, whichincrease the amount of surface area on substrate 101 and may openinterstitial spaces in cellulosic materials.

In additional or alternative embodiments, substrate 101 is treated by adevice (not shown) that scarfs the edges, i.e., processing the edges sothat they form an angle of 45°. Alternatively, the edges may beprocessed by a device (not shown) to form a beveled or rounded edge.

Subsequent to scuffing and/or scarfing or beveling, substrate 101 ispassed along a transport path to transport device 112, which movessubstrate 101 to a first roll coater 120, where substrate 101 is coatedwith a first coating or a pre-coating of a fire-resistant material.First roll coater 120 may deposit the pre-coating of fire-resistantmaterial using a single top coater, which may include a spreader roll,or may deposit a first coating of fire-resistant material using a singleside roll coater, a reverse single side roll coater, a flow coater, or aspray coater, for example. As the coated substrate 101 passes throughand out of first roll coater 120, transport device 122 delivers coatedsubstrate 101 to second roll coater 130. The first coating orpre-coating will typically be only a fraction of the total amount offire-resistant material applied to a substrate, e.g., 10% to 40%,preferably, 20% to 30%.

Second roll coater 130 is a standard direct roll coater modified toinclude an unwind stand to hold a roll of carrier material, such as aweb of fiberglass veil and a path for leading the web into the nipbetween the coating rollers. The web of veil material is pulled into theroller nip and passed through a bath of slurry formed in the spacebetween the rollers so that the glass fiber veil is impregnated with theslurry. The fiberglass veil impregnated with fire-resistant material isthen fed out from the nip and deposited on a top surface of coatedsubstrate 101 as it passes between two rollers. The contact and surfacetension forces between the coated substrate and the impregnated veilprovide sufficient “stiction” to help draw the impregnated veil out ofthe nip and hold it down on the coated substrate. The roller speed mayassist in the delivery of the impregnated veil to the substrate at arate matching the substrate transport. The impregnated fiberglassmaterial and the pre-coating on substrate 101 combine intimately to forma continuous bond.

If a continuous fiberglass veil has been applied at the second rollcoater 130, at some point in the process the substrates need to besingulated. For example, when the transport direction of the coatedsubstrates is changed, e.g. from longitudinal travel to lateral travel,the adjacent substrates need to be separated from one another beforechanging direction. This may be done by a suitable separating apparatussuch as a scissor, laser, cutting bar, router blade, or water jet cutter(not shown in FIG. 1).

According to FIG. 1, the veiled and coated substrate 101 is thentransported out of second roll coater 130 to transport device 132, whichsubsequently feeds substrate 101 to third roll coater 140. Third rollcoater 140 may provide an additional coating of fire-resistant material,may finish the material to a desired thickness or texture/smoothness, ormay treat the substrate using any suitable method or combination ofmethods. The actions in the third roll coater may be designed to ensurethe proper amount of material has been applied to meet productspecifications, to achieve cosmetic effects for the surface of thecoated substrate 101 not fully achieved in prior steps and/or to helpcontrol the dimensions and/or the volume of the finished substrate. Theaforementioned coaters are discussed further below in relation to FIGS.3-5.

In some embodiments, subsequent to receiving coatings, the raw edges ofthe substrate 101 are wiped with slurry. However, the raw edges may haveslurry applied at any suitable stage in the production process.

Transport device 142 receives each substrate 101 from third roll coater140 and dispatches each substrate 101 laterally to oven 150, where thecuring process is initiated. Oven 150 may take a variety of dimensions,but for the purposes of this embodiment, oven 150 is about 40 feet longand 10 feet wide, or at least wide enough to accommodate substrate 101lengthwise or widthwise. The top of the oven may include infrared orother suitable heaters to deliver heat into the coated substrate. Fromoven 150, coated substrate 101 passes to transport device 152 which mayinclude an elevator with paddle handles in order to lift and load coatedsubstrate 101. Transport device 152 delivers coated substrate 101 toconditioning area 160 so that the coatings on the substrate may cure toform a cementitious coating and adhere to the substrate. This is becauseoven 150 initiates curing but does not cause the coating to cure fully.Thus, in the conditioning area, as the coating further soaks into thesubstrate while curing, a stronger, deep, penetrating bond between thecoating and the substrate results. More specifically, the deep,penetrating bond forms between the surface of the substrate and thecured coating of cementitious material. Racks may be placed on aconveyor system, e.g., rail-type conveyor, roller conveyor, chainconveyor, or cart system and be slowly pulled through a conditioningarea, and may hold the substrates, for example, for up to 3 hours inorder to allow for a slow cure and for forming an intimate penetratingbond between the fire-resistant material and coated substrate 101.Coated substrate 101 is finished in finishing area 170, e.g., trimmingand labeling, and stacked in stacking area 180. As noted, in finishedproduct, the cured coating may vary between 10-125 mils (weight about2.1 lbs.-27 lbs. per panel of 32 ft²).

A control center 190 may be implemented according to embodiments of thepresent invention in order to sense and control the parameters of theproduction process. For example, control center 190 may adjust ovendwell times, or may adjust the speed at which one or more pieces ofequipment operates so that overall production is conducted at thedesired rate. Given the interdependence of the various operations, itmay be necessary for the control center 190 to monitor and changetransport speeds, as well as to control flow of fire-resistant materialsby pipe from one or more sources to the roll coater where it is to beused. In addition, control center 190 may control oven temperature orother equipment variables for production in real time so that, forexample, changes in ambient conditions that may affect drying and curingof the fire-resistant substrate can be accommodated. In another example,control center 190 may control the speed of conveyors and rollers sothat lags in production can be accommodated for. Control center 190 mayalso collect data for use in statistical process control (SPC) orquality control processes in order to give feedback on the line, forexample.

FIG. 2 depicts a schematic block diagram view of another production line200 that may be implemented according to embodiments of the presentinvention. Production line 200 includes a series of coater stations todeposit fire-resistant coatings in slurry form in several stages. Theproduction processes include delivering a substrate 201 to first station210, which deposits a first slurry 211 on substrate 201. The firstslurry is formulated to cause wetting of the substrate as a steppreliminary to the later stations.

Production line 200 continues by passing coated substrate 201 into asecond station 220 which includes roller 221 for guiding material fromweb stock 202 (a carrier material, such as a fiberglass veil), into andthrough the nip between rollers 222 and 223 where impregnation of theweb stock 202 with a fire-resistant material slurry 224 takes place.More specifically, the impregnation occurs at the top portion of rollers222 and 223 and as the material passes through rollers 222 and 223.Rollers 222 and 223 are also used for directing the impregnated webstock 202 on to wetted substrate 201. Slurry 224 is contained in a nipreservoir or a “virtual bath” in the space between the top portion ofrollers 222, 223. This type of reservoir has been found to be sufficientto produce the desired impregnation of the web material passing throughthe nip between rollers 222 and 223. The amount of slurry to bedeposited on web stock 202 from the reservoir of slurry 224 isdetermined in part by the distance between rollers 222 and 223, anadjustable dimension in roll coaters. The “virtual bath” may also beconsidered a vertical bath, because the web stock 202 is impregnatedwith slurry as it passes generally vertically through the bath ofslurry. As the impregnated web stock 202 comes out of the nip and laysonto the wetted substrate 201, the slurry in the web stock begins tobond with the slurry on the wetted substrate.

Following the coating processes described above, the web stock 202 maybe cut at the edge of the substrate 201 (between substrate pieces) atcutter 225, which may include a water jet cutter, for example. Cuttingthe web stock to separate adjacent substrates reduces the likelihood ofbreaking the web/substrate bond due to forces transmitted by the webfrom movement of an adjacent substrate. In addition, coated, veiledsubstrate 201 is able to move independently of the veil and of the othersubstrates directly after substrate 201 exits the second station 220where the veil was deposited.

Where finishing is desired, production line 200 passes the web-coveredand slurry-coated substrate 201 to a third station 230 which deposits athird slurry 233 on coated substrate 201. The third slurry 233 isintroduced to rollers 231 and 232 at a top portion of the rollers, andthe amount of slurry that is deposited on coated substrate 201 isdetermined by the nip of the rollers, or the space between rollers 231and 232. The third station 230, in addition to depositing a third layerof slurry 233, serves to smooth or texture and to help control thedimension of the materials on coated substrate 201.

The coated substrate 201 is then transported from the third station 230to oven 240 to add heat to the fire-resistant coating layers to initiatethe coating curing process and then transported to conditioning area 250where the coatings can continue to undergo the curing process.

One dimension of process control in the system just described is todetermine the weight of fire-resistant material applied to a substrate201 as it passes through the stations 210, 220, 230. In one embodiment,the substrate 201 may be weighed before entering the first station 210and after exiting the second station 220 and/or the third station 230.For example, if substrate 201 is to receive a target amount offire-resistant materials, the uncoated substrate may be weighed todetermine the starting weight and after exiting third station 230 todetermine whether the current production settings yield the targetamount of fire-resistant material on the coated substrate materials,e.g. weight (0.3-0.75 pounds per square foot) and/or thickness (10-125mils). Alternatively, in another embodiment, the thickness of thecoating may be measured by mechanical means such as a roller caliper orby passing sound waves through the coating. The production process mayremain continuous even while weighing the substrates because conveyorswith weighing capabilities may be used as weighing stations while at thesame time transporting or redirecting the substrate through theproduction line.

In certain embodiments of the present invention, the substrates to becoated are separated by a short distance when undergoing application ofthe impregnated web, i.e., ¼″ to ½″ apart, and transported along theproduction line into and through the coater that applies the impregnatedweb while maintaining the small separation. This minimizes materialwaste and permits the process to be near-continuous notwithstanding theseparate substrate units. Upon cutting the web material between closelyspaced substrates, the substrates may continue to be closely spaced ormay be transported at a greater separation distance with respect to theother substrates.

In one embodiment of the present invention, the substrate is coated withonly two layers, a first wetting layer of slurry and a secondimpregnated veil borne layer. According to this embodiment, once theslurry-impregnated veil is deposited onto a pre-coated substrate, theveil is cut at the trailing edge of the substrate to separate one coatedsubstrate unit from the next following one, and the separate coatedsubstrate is subsequently weighed and transported to an oven in order toinitiate curing of the slurry material. The heated coated substrate maybe transported to a conditioning area and subsequently may be sent to afinishing area.

The impregnated veil layer may be adequately smooth or it may be maderough intentionally. Having a rough outer surface once thefire-resistant material cures may be useful for subsequent applications,e.g., when bonding the substrate with other finish layers such asmelamines or other laminates or plastic films, wall papers, veneers, orother layers suitable for depositing on cured fire-barrier material.Here an adhesive or glue would normally be used, taking advantage of therough surface. Alternatively, a smoother surface may be used for bondingonce the substrate exits an oven area and before curing is completed.For example, another layer such as another substrate, a laminate, orveneer may be laid on the coated surface of the substrate while it isstill wet and before the coating can significantly cure. The laminatedor veneered material may form a bond with the uncured coating on thesubstrate, and the laminated or veneered panel may then be stored in aconditioning area for further bonding and curing.

The above-described production lines are only a few embodiments ofproduction lines that may be implemented according to the presentinvention, and are not intended to be limiting. For example, aproduction line may include an area for adding a subsequent substrateover the coated and veiled substrate in order to form a product having afire-resistant material between the two substrates rather than on anexposed side of the substrate. The example production line may befurther configured to coat one or more of the exposed sides of thesubstrate. In another example, the production process may allow asubstrate-exposed side of a pre-coated substrate to be covered by acoated side of another pre-coated substrate. In yet a further example, abare substrate may be covered by a layer of Mylar or other polyesterfilm and then may be coated with a fire-resistant material impregnatedweb. The polyester film serves as a releasing layer allowing theformation a web-impregnated fire-barrier product without a substratesuch as a wood panel. In still a further example, the veil material maybe cut-to-size and then be impregnated by the slurry of fire-barriermaterial. The pre-cut impregnated veil by then undergo subsequentprocessing steps or may be a complete product after receiving theslurry. From the aforementioned examples, one skilled in the art candiscern a variety of production line configurations that may beimplemented according to embodiments of the present invention.

Roll Coaters. FIG. 3 is an illustration of a reverse roll coater 300that may be used, according to embodiments of the present invention, inorder to deliver a coating to a substrate. Roll coater 300 includesframe 2 that supports chrome plated coating roll 16, and chrome plateddoctor roll 17, which delivers a slurry to the coating roller. Thethickness of the coating layer may be controlled by adjusting the nipdimension between the coating roller 16 and the doctor roller 17 and byadjusting the speed at which the coating roller 16 rotates relative tothe movement of the substrate. Slurry material is delivered to the areabetween the rollers 16, 17 and nip guard 18 by material feed line 76. Asubstrate (not shown), such as a OSB or plywood panel, is fed into rollcoater 300 via in-feed, which includes fixed feed table 22. Thesubstrate is coated with a slurry as it passes between coating roll 16and resilient feed roll 28, and the coated substrate exits roll coater300 via fixed out-feed table 22. Any excess material reaching the areaof the out-feed table 22 is collected in material overflow system 79 andrecycled. According to embodiments of the present invention, roll coater300 may be used to apply a first coating of fire-resistant material to asubstrate and/or may be used to apply a third layer of fire-resistantmaterial over previously deposited layers on a substrate. Alternatively,other coaters such as flow coaters may be substituted for the reverseroll coater for the application of a first or third layer offire-resistant material.

FIG. 4 is an illustration of a top roll coater 400 that includes anunwind stand 26 for supporting roll 27 of pliable veil of fibrousmaterial for subsequent delivery to a substrate via an impregnated sheetof veil or carrier material. Top roll coater 400 is used to deliver thesecond veil-borne layer of fire-resistant material to a substrate.Material from roll 27 passes along an edge guide alignment system 23,which may utilize an optical sensor in order to confirm that thematerial will align with a substrate passing through roll coater 400.From edge guide alignment system 23 the material passes between pivotingroll nip guard 13 and into a “virtual bath” area (the roller area justabove the nip) holding viscous fire-resistant fluid. The viscousfire-resistant fluid is drawn into the veil material and coats thefibers, and the amount of fluid that impregnates the material isdetermined by the space between coating roller 1 and doctor roller 2.Once the coated material passes between rollers 1 and 2, the coated veilmaterial is coupled to a substrate, i.e., an OSB or plywood panel,passing through roll coater 400 via in-feed table 10.

Immediately before the substrate enters roll coater 400, the substratemay be coated with a viscous fire-resistant material, e.g. via reverseroll coater 300. In this case, the coated material from roll coater 400combines with the uncured/undried first coating of fire-resistantmaterial on the substrate as it passes between coating roll 1 and feedroll 3. Because the fire-resistant material from both the veil materialand the substrate are wet and uncured, and because the wetfire-resistant material includes adhesive properties, blending the twocoats of material into an intimate combination may be accomplishedwithout the necessity of additional glues or adhesives. Subsequent tocoupling the coated substrate and saturated veil material, the substrateexits roll coater 400 via out-feed table 11. Because thesubstrate/pliable veil material interface arises as the coated substrateis moving through roll coater 400, roll coater 400 is able to deliverthe pliable sheet of material to the substrate without positivepressure; instead the pliable sheet material need only be unwound fromroll 27. Gravity helps pull the impregnated veil down to the coatedsubstrate and friction and surface tension hold the impregnated veilonto substrate. The impregnated veil is delivered to the substrate atthe same rate the substrate moves in an advancing direction through rollcoater 400. Roll coater 400 may be powered by any suitable meansincluding via a drive motor 6.

FIG. 5 is a view of the area of roll coater 400 that delivers afire-resistant slurry impregnated veil material to a substrate. In orderto become impregnated, the material 14 passes nearly vertically througha “virtual bath” 15 which is defined by the roller area above the nip ofrollers 1 and 2. Slurry material is sprayed, poured, or otherwisedeposited in an area just below pivoting roll nip guard 13 at a set ratethat allows enough slurry to be present for the material 14 to becomeimpregnated with slurry in the “virtual bath” 15, while at the same timeensuring that the “virtual bath” 15 area does not overflow. The “virtualbath” 15 is maintained on the edges of the rollers by additional nipguards (not shown), which serve as dams to keep slurry material fromspilling off of the side of the rollers. According to FIG. 5, asubstrate material 14 to receive the impregnated material enters rollcoater 400 at in-feed table 10 where it passes under barrier guard 12and doctor roll 2. The impregnated veil material is delivered to thesubstrate from the “virtual bath” 15 area between coating roller 1 anddoctor roller 2. Feed roller 3 rotates in a direction that leads thesubstrate through roll coater 400. The slurry-coated substrate material14′ passes out of roll coater 400 via out-feed table 11. Roll coater 400delivers fire-resistant slurry to a veil material 14 as it passesvertically, or generally vertically into the “virtual bath” 15.

FIG. 6 is a is a view of the area of roll coater 400 that delivers afire-resistant slurry using an alternate roller pair that coats afire-resistant slurry onto a carrier veil. The components of FIG. 6 thatare the same as FIG. 5 are numbered in the same fashion as FIG. 5.Whereas in FIG. 5, the axes of the rollers 1 and 2 of the roll coaterare in approximately the same horizontal plane, in FIG. 6, the axis ofone roller, roll 1 a, is higher than the other, roll 2 a. This permitsthe veil material 14 to approach the roller nip at a non-vertical, acuteangle to receive the slurry coating. The slurry is fed to the upper sideof the nip, just below pivoting roll nip guard 13. The positioning ofthe rollers permits a reservoir of material to reside in the nip therebyforming “virtual bath” 15. This angle of approach may be useful in someenvironments and permits the web to exit in a direction that is morealigned with the direction of travel of a substrate. The coated veil 14′exits the coater out-feed table 11. In some embodiments, an additionalguiding roller 16 guides the coated veil 14′ to out-feed table 11. Thismay enable the coated veil 14′ to be controllably coupled to thesubstrate passing through the coater via infeed table 10.

The fire-resistant mixture may vary according to differing conditions onthe production line. The mixture typically will have a MgCl brine thathas a specific gravity between 1.22-1.26, but also includes an amount ofH₂O in order to prevent it from being “water starved,” which may involveadding “water of convenience” before coating processes. The amount of“water of convenience” added depends on the varying conditions of theproduction line. Each coater 300, 400 receives a supply of slurry from amixing station. The slurry is delivered from the mixing station to aslurry holding tank from where it is pumped to individual tanks at eachcoating station. Depending on the function of the coater, the slurry isdelivered to the surface of one or more rollers or to a “virtual bath.”When delivered to the roller surfaces, the nip and the speed of theroller determine the thickness of the layer deposited on the substrate.When delivered to the “virtual bath,” which is considered the areadefined by the nip area and the roller area above the nip, the thicknessof the resulting impregnated veil layer depends on the nip and on theproperties of the veil material to be impregnated in the “virtual bath.”It should be noted that although the nip area in the “virtual bath” willbe slightly wider than the veil material, slurry will not freely flowthrough the nip, because the veil passing between the rollers blocks theviscous slurry from freely exiting the nip and allows the virtual bathto be maintained in the roller area above the nip. Excess slurrymaterial in both coater 300 and 400 is collected in a drip pan where theslurry is pumped away and recycled.

Various coaters may be used to coat fire-resistant materials on and intopliable veils to saturate them thoroughly. For example, FIG. 7 is anillustration of pan bath coater 700 which may be used to coat a pliableveil. The pan bath 710 of pan bath coater 700 is a container-definedbath (e.g., pool in a rectangular pan) that contains a slurry offire-resistant material (not shown). According to this example, the veilmaterial 701 is delivered from a spindle roll 711 to the pan bath 710via a series of rollers 702, 703. The rollers 702, 703 are configured toenable the veil material 701 to be threaded around the rollers so thatthe veil material 701 is directed into the pan bath 710 where the veilmaterial 701 runs through the bath and is impregnated by thefire-resistant material. The impregnated veil material 701′ is thenthreaded through another series of rollers 704, 705 that direct theimpregnated veil out of the pan bath and to a processing area. In FIG.7, as the impregnated veil passes out of the bath via rollers 704, 705,above the terminal end of the bath, the impregnated veil 701′ isdirected to a substrate (not shown) via rollers 706, 707 for subsequentbonding with the substrate and is directed out of pan bath coater 700via feed roller 708.

Results. According to methods described above, a fire-resistant panel isproduced faster and more efficiently, because a coated mat or veil, suchas a fiberglass mat or veil, is applied to the substrate, such as anoriented strand board or plywood panel without producing a large amountof excess. The mat or veil is impregnated and/or coated withfire-resistant material and then disposed on a surface of a substrate.This method of fire barrier panel production provides advantages overother methods because the production steps that coat and lay the mat orveil on the substrate may avoid repetitive spraying and/or“overspraying” of the cementitious fire-resistant materials, therebyyielding a cleaner manufacturing process. In addition, the mat or veilcoated with fire-resistant materials may be precisely placed on thesubstrate in order to prevent or reduce the amount of material thatextends beyond the substrate, thereby reducing waste. Further the mat orveil may be impregnated with selected, predictable amounts offire-resistant material so that targeted fire resistance result may beachieved. Finally, the cured fire-resistant layers may add strength tothe coated substrate panel, such that the coated panel will deflect lessand be less damaged by deflection agents such as wind, snow, and/orseismic loads.

Further, according variations of the methods described above, thefire-resistant products that may be produced include a cured magnesiumoxychloride complex that is materially coupled to the mat or veil.Material coupling, for purposes of the present invention, includesassociating with, contacting, adhering to, becoming integral with,embedding, migrating, saturating, impregnating, coating, or the like.According to certain embodiments, the complex may compriseMgCl₂.mMg(OH)₂.nH₂O; where m is between about 3 and about 7, and n isbetween about 6 and about 10. In other embodiments, m is between about 4and about 6, and n is between about 7 and about 9. In a particularembodiment, m is about 5 and n is about 8 which yields a fire barrierproduct with a desirable level of stability, hardness, and amount of H₂Owithin the cured complex. Furthermore, it has been found that in theparticular embodiment described above, where m is about 5 and n is about8, the magnesium oxychloride complex when combined with a mat or veiland with wood or cellulosic-based materials, achieves desirablefire-barrier performance. Additional embodiments may include depositingfurther layers of the magnesium oxychloride complex over or on the mator veil, or over or on the wood or cellulosic-based materials in orderto yield fire-barrier products having a desirable property, such as adesirable thickness or texture. Depositing layers over or on mat orwood, according to the present invention includes depositing a layerthat makes contact with the mat or wood, which may include a top surfaceof the mat or wood, for example.

In yet a further embodiment, a mat or veil having been impregnated witha slurry may be coated with a further layer of slurry which may then bepartially cured and used in subsequent applications, or may be fullycured, in which case the product may or may not be used, in subsequentproduction processes. Used in subsequent production processes, themagnesium oxychloride may form a layered fire-resistant product on asubstrate. Such a product may include a glass-based web; a magnesiumoxychloride complex materially coupled to the web, where complex is:MgCl₂.mMg(OH)₂.nH₂O; where m is between about 3 and about 7, and n isbetween about 6 and about 10; a layer of magnesium oxychloride complexmaterially coupled on the web, in which the complex comprises:MgCl₂.mMg(OH)₂.nH₂O; where m is between about 3 and about 7, and n isbetween about 6 and about 10; and a substrate materially coupled to thelayer of magnesium oxychloride complex. It should be understood that theuncured precursors to the magnesium oxychloride complex are used toimpregnate and subsequently coat the web, and therefore, the slurry inthe web and the slurry of the slurry layer are able to form a continuousmaterially bond over the entire substrate.

Utilizing a web of mat or veil material with the magnesium oxychloridecomplex provides a layer of fire barrier material with reinforcingproperties and added structural strength over non-continuous coatings offiberglass because of the continuous nature of the mat or veil.Accordingly, a lesser weight of fiberglass mat or veil provides an equalor greater amount of structural strength over the non-continuous coatingof fiberglass.

The performance of a fire barrier product having MgCl₂.mMg(OH)₂.nH₂Oideally drives off chemically bonded H₂O molecules at about 450° F. or230° C., and at about 1200° F. or 650° C., the Mg(OH)2 molecule beginsto revert to MgO and H2O, releasing the bound hydroxide molecules andthereby enabling additional H₂O to be shed at higher temperatures.

While the present invention has been described in the context of coatingand impregnating fire-resistant substances on and in materials, itshould be understood that any substance may be used to coat materialsusing methods according to the present invention. For example, generallycementitious slurries may be used to coat webbed materials. However, anysuitable viscous material may be used to coat pliable fabrics accordingto methods of the present invention. Variables in production lines mayalso be altered hi order to yield a desirable product using the coatingmethods of the present invention.

The foregoing descriptions of specific embodiments of the presentinvention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteaching. The embodiments were chosen and described in order to bestexplain the principles of the invention and its practical application,to thereby enable others skilled in the art to best utilize theinvention and various embodiments with various modifications as aresuited to the particular use contemplated.

All patents, patent applications, publications, and references citedherein are expressly incorporated by reference to the same extent as ifeach individual publication or patent application was specifically andindividually indicated to be incorporated by reference.

1-32. (canceled)
 33. A method for providing a cementitiousfire-resistant substance onto a substrate comprising the steps of:pre-processing a substrate to increase surface area available forbonding with the cementitious fire-resistant substance; weighing thesubstrate; depositing a layer of cementitious fire-resistant substanceon the pre-processed substrate in slurry form to initiate a penetratingprocess of the cementitious fire-resistant substance into thepre-processed substrate; providing a selected amount of cementitiousfire-resistant substance in the slurry form on a pliable carrier veil;depositing the pliable carrier veil on the substrate, wherein thecementitious fire-resistant substance in slurry form on each of thesubstrate and the pliable carrier veil blend into a continuous layer;and determining a fire resistance of the substrate with the depositedpliable carrier veil having a selected amount of cementitiousfire-resistant substance per square unit of substrate by weighing thesubstrate with the pliable carrier veil and comparing its weight withthe weight of the substrate.
 34. The method of claim 33, wherein thesubstrate is comprised of cellulosic material, and pre-processing thesubstrate comprises opening interstitial spaces in the cellulosicmaterial.
 35. The method of claim 33, further comprising applying heatto the substrate with the deposited pliable carrier veil to initiate anaccelerating curing process of the cementitious fire-resistantsubstance.
 36. The method of claim 35, wherein the amount of heatdelivered is measured by measuring a surface temperature of a topsurface of the substrate having the deposited pliable carrier veil. 37.The method of claim 36, further comprising comparing the measuredsurface temperature with a target surface temperature and removing thesubstrate having the deposited pliable carrier veil from the appliedheat upon the top surface reaching the target surface temperature. 38.The method of claim 35, further comprising controlling a temperature ofheat, humidity, intensity of heating, air speed or substrate transportspeed in connection with applying the heat to initiate the acceleratingcuring process.
 39. The method of claim 33, further comprisingcontrolling the fire resistance of the substrate having the depositedpliable carrier veil thereon by adjusting an amount of cementitious fireresistant substance deposited on the substrate or adjusting the selectedamount of cementitious fire-resistant substance provided on the pliablecarrier veil.
 40. A method for coating a cementitious fire-resistantsubstance onto a substrate comprising the steps of: providing an amountof a cementitious fire-resistant substance in a slurry form to a pliablecarrier veil, wherein the cementitious fire-resistant substance isdeposited in and on said pliable carrier veil web to form a veil layer;depositing a layer of cementitious fire-resistant substance on asubstrate in slurry form to initiate a penetrating process of thecementitious fire-resistant substance into the substrate; delivering theveil layer uncured to the substrate surface such that the substrate andveil layer are coupled by the cementitious fire-resistant substance onthe veil layer and the substrate forming a continuous layer; applying aninitial amount of heat to the coupled substrate and veil layer forinitiating a curing reaction in the cementitious fire-resistantsubstance; removing the accelerating heat to allow the continuous layerof cementitious fire-resistant substance to slow cure to promote acementitious bond with the substrate surface; and providing thesubstrate coated with the veil layer with a selected fire resistance bycontrolling the amount of said cementitious fire-resistant substancedeposited in and on said pliable carrier veil, controlling a rate atwhich said slurry form of cementitious fire-resistant substance isdeposited on the substrate, controlling a rate at which the uncured veillayer is delivered to the substrate, controlling a rate of transport ofthe substrate as the substrate and the veil layer are coupled, orcontrolling a period of time the initial amount of heat is applied tothe coupled substrate and veil layer.
 41. The method of claim 40,wherein the selected fire resistance is provided by sensing a parameterof the cementitious fire-resistant substance affecting a cure rate ofthe cementitious fire-resistant substance and adjusting one or more ofthe controlled rates or amount of time based on the sensed parameter.42. The method of claim 40, wherein the selected fire resistance isprovided by sensing ambient conditions, and in response, adjusting oneor more of the controlled rates or amount of time.
 43. A productcomprising a substrate and a cementitious fire-resistant substanceprovided thereon, the product produced by the process comprising thesteps of: forming a nip between two rollers; supplying to the nip apliable carrier veil in a traveling web having a selected thickness;supplying said cementitious fire-resistant substance to the nip inslurry form, to form a reservoir of said cementitious fire-resistantsubstance defined by said nip of two rollers; controlling the amount ofsaid cementitious fire-resistant substance impregnated in and on saidpliable carrier veil, wherein controlling comprises setting a nipdimension between said two rollers according to the selected pliablecarrier veil thickness such that the two rollers exert a pressure on thepliable carrier veil that determines an amount of the cementitiousfire-resistant substance passing with said pliable carrier veil throughsaid nip of the two rollers and impregnate the pliable carrier veilexiting the nip to form a veil layer effective to provide a selectedfire resistance; delivering the veil layer uncured to a surface of thesubstrate by advancing the substrate and veil layer at the same ratesuch that the veil layer and substrate are coupled in a continuous feedby gravity and slurry surface tension of uncured cementitiousfire-resistant substance in the veil, without positive pressure on theveil layer during such coupling; applying an initial amount of thermaltreatment to the impregnated veil layer sufficient to accelerate acuring reaction in the cementitious fire-resistant substance; andremoving the accelerating thermal treatment after a predefined period tocontrol water loss from the veil layer and allow the cementitiousfire-resistant substance to slow cure to promote a cementitious bondwith the substrate surface.
 44. The product according to claim 43,further produced by the steps comprising: coating a first layer of acementitious fire-resistant substance on the substrate; and wherein thestep of delivering the veil layer comprises depositing said veil layeruncured as a second layer over the uncured first layer of cementitiousfire-resistant material, said first and second layers undergoing theaccelerating heat and slow cure together.